Electrical unit closure



G. W. CARPENTER ELECTRICAL UNIT CLOSURE.

March 8, 1949.

Filed Juno 15; 1945 n HIHIYI i IN1/EN TOR'. 61m): Khrmier fram/fr Patented Mar. 8, 1949 ELECTRICAL UNIT CLOSURE Glenn W. Carpenter, Indianapolis, Ind., assignor to P. R. Mallory & Co., Inc., Indianapolis, Ind., a corporation of Delaware Application June 15, 1945, Serial No. 599,656

3 Claims.

Figure 3 is a partial view, in central section, of 'the assembly of Figures 1 and 2, with the housing, cover, and seating ring in assembled relation with each other;

Figure 4 is a partial view, in central section, of an alternate structure of this invention;l and Figure 5 is an illustration of the form of a tooth portion of a housing cover securing ring of this invention.

This invention may be used with electrical unit containers or housings in a variety of materials, shapes and forms; the particular example herein described as an illustration is an electrolytic condenser in a cylindrical housing of molded Bakelite having one end integrallyA closed and the other end closed by a cover which is secured to the housing in accordance with this invention.

The electrolytic condensenunit embodying this invention comprises the Bakelite housing, in which the customary roll of condenser foils is contained, a cover for the housing, and a device for securing the cover to the housing.

As illustrated in Figure 1, the Bakelite housing is indicated by the number I, the cover by 2, and the cover securing device, or ring, by 3. The condenser foil roll is not shown since the invention relates to the housing and its closure, rather than its contents.

The housing I is preferably formed by molding a suitable synthetic insulating resin but any other desired method of forming or other suitable materials such as a plastic or metal may be used. A suitable shape for the housing I is as a circular cross-sectional cylinder but it is within the scope of this invention that the housing cross-section may be of any desired curved or straight sided shape, such as square, for example.

The housing I is formed with an integral base at one end 4 and has its other end open with an annular end face 5. The inner wall of the housing is stepped so that the housing wall adjacent the housing open end has a uniformly reduced thickness with respect to the rest of the housing wall, and so that an unbroken smooth inner surface 8 is provided adjacent the open end of the housing, leading to an inner annular shoulder 1 of sufficient width to provide a substantial seat for the cover 2.

The shoulder 1 faces the open end of the housing I in substantial parallelism with the housing end face 5. The shoulder surface may however be at any desired angle with respect to the housing or the housing end face 5.

The cover 2 is formed to lateral dimension and contour as defined by the inner housing wall 8 so that the cover may be inserted in the open end of the housing I to rest on the shoulder 1 and to be in snug fitting relation with the inner housing wall 8.- The thickness dimension of the cover 2, and the distance of the shoulder 1 from the housing end surface 5 are arranged so that the cover 2 may rest on the shoulder 1 with the outer surface of the cover a substantial distance inside the housing I.

The cover 2 comprises a disc of a synthetic insulating resin material or of similarly suitable non-conductive material, and has a disc 8 of sheet rubber or the like, of the same diameter as the disc 2 but of less thickness, strongly secured by cementing or other suitable means to its inner face so that in assembly the rubber sheet 8 has an annular peripheral portion of its free face in engagement with the housing ledge 1. Also, in assembly, the cover 2 is under pressure from the securing ring 3, against the housing` shoulder 1, and the rubber sheet 8 is compressed so that its periphery, which in disassembly is coincident with that of the cover disc 2, is forced radially outwardly into the angle formed by the junction of the inner housing wall B and the shoulder 1, thus providing a very efficient closure seal which prevents the entrance of impurities into the condenser housing and the escape of electrolyte or gases from the condenser housing.

Connection is made from the condenser foil plates to the outside of the condenser housing through two aluminum pins 9 which extend through the cover 2 and the rubber disc 8. The pins 9 are preferably located on a diameter of the cover 2, each substantially equidistant from the cover periphery and its center. The inner end of each pin 9 extends through and is headed over a ribbon-like condenser foil connecting strip I0 also formed of aluminum and the outer end of asesoria each piu extends through euri ls heaolefl over a connection terminal angle hraclret li or tiuaecl orass or steel and a steel loci: washer G2. ".he hearilugover or the plus hoth expands the gains radially cfu compresses the cover and. the ru`b= clisc inwardly against the plus to elcieutly seal the cover and ruhe-er disc openings through which the joins esterni. The connection tern minal angle hracizets il each have a i'lat uo standing portieri which extends somewhat heyohcl 'the cual il or the condenser housing l tvheri the housing ariel the 'cover 2 are iu assembly. .an opening provided iu each ci the upstarlclihg portions oi the terminal 'il for the re ceptlou au outside ,connection wire to he soiclerecl or otherwise secured. the terminal hracheh The plus Q auo'i the eohuectiou. strips iii are rormell or aluminum slrice the condenser ltoil is normally aluminum. Electrolytlc action hetweeu ttvo `clissiruilar metals within the housing is thus svol-desi.,

cover securing ririg t is preferably formed oi resilient metal such as spring steel. lau the assembly of the condenser Unit, the cover is first piaceri in the operi ena oi the housing l, against the shoulder l, ami the securing ring is their rorceri luto the operi earl of the housing l, the cover 2, to compress the rubber disc il in forming a seal between the cover 2 and. housing as has been described. heroin. The peripheral edge portions o the securing riug 3 reslllently engage the iruier Wall E: o the housing i to .strongly hold the ring 3 against the cover il iu securing the cover il to the housing i and irl malutairlius the seal provided between the rubber also ariel the iurier housing laces cora= prisirlg the shoulder l and the wall The securing ring 3 is the general shape of a frustum o e, come, aucl'is assembled in the open euri o the condenser housirig i' with the rmsturu toi:` engaging the cover 2 and with the normal or true lease of the cone facing outvvarcl and located within the housing iu spaced relatiou with the housing euri surface le. lihe prez ierrec'l rorm of securing ring is shown irl Figures l, 2, 3, 5 and comprises arl annular substantially itat portion i3 defining the top of the frusiroun ancl having, at regularly spaced points on ts periphery, substantially hat teeth lo all exteritllug from the auriular portion i3 in similar outwardly angular ariel clirectional relationship rwith the ariuular portion i3 to efectively eiene the side surface of the rrustum with their outer races the hase of the i'rustum with their chris.

The securing ring il may loe formed by drawing a shallow cup from sheet Stoch, and forming an annular spring steel portion i3 with spaced. peripheral teeth. and thereafter bending the teeth to the desiree?. angle with respect to the' ourlular portion i3. The surface junction of the outer ariel inner races of the teeth lll with the portion. i3 may he rouricleel or angular as olesirecl. The diameter of the ring including the teeth must se suicieht as hlahlreci out to permit heuciirig of the teeth to the desired angle without reducing the overall diameter to the diameter clerliierl hy the inner wall of housing l. The center of the ring is removecl to prevent ihterference with the conrlectiouA plus il and terminal brackets il. Before the spring ring is assemhleci iu the housing l the ring overall rliarna eter ls greater than that cleuecl hy the housing trail il. lo assembly, the ring teeth lo engage the wall t and are Deut inwardly. This eu-= sagement is preferably, shown iu Figure il, between the radially outermost edges oi the tree ends or the teeth is arid the housing surface This edge engagement may he at che or more points on the outer edge of each tooth, depending upon the form of the teeth, their angle with rcspect to the annular portion i3, and the forro of the housing surface Lirie contact oi the teeth edges, or surface contact 'of the tooth enel or outer faces, with the housing surface,l is .vlthlri the scope of this invention. The resilient teoa clency or the teeth to returrl to their formeel Jpositions holcls the ring securely irl place in the operi end of the housing il, with the irustum top deiining surface or the annular particu i3 uucler pressure against the housing cover il..

Referring to ligure 5, it has Iheen iouutl that au eective formation for the spring ring teeth lil is with their side edges lil and il lying in radial planes with respect to the ring i anti with their peripheral edges lil arcs deilned by the radial planes or side eclges and l'l with respect to the peripheral circle oi the ring 3 about the free chris or the teeth lll as indicated by the dotted llrle This lorrn provides the teeth ill with acute angles hettveeu the side edges it and il and the euri colse lf3, and is particularly useful when the ring il is plated, as with nichel, cadmium, copper or other suitable material, to prevent corrosion.

Thus, the engagement between the teeth lo and the housing Wall il is primarily at 'the corA hers formeel by tooth side edges l@ ariel il with the end edges assuring more positive cori:J tact with the wall o and a tendency for the tooth corners toclg into the wall o, and providing a very secure assembly.

In stead of the chord tooth described above, a radius tooth may he used ii the ring is made from a material which does hot require plating. The radius tooth, if substituted irl Lligure 5, would have its outer peripheral edges lying along the circle i9.

The alternate structure assembly oi Figure ll is an assembly like that described above exceiit that a solid spring ring Without the teeth shown in ring 3, is useci to secure the cover to 'the condenser housing i. Ring 2@ is formeel icy drawing and centrally perforating a shallow Cup to provide the solid ring'with a peripheral angle portion iii and a plane surface annular portieri Like the spring ring 3, ring 2li is formeel oversize with respect to the inner housing di ameter deineol by wall il, anol iu assembly the angle portion 2l is forced inwardly ariel the ring is heldin place with the annular portion 222 pressn ing the cover 2 against the housing shoulder l hy the spring engagement of the angle portieri 2l against the housing Wall o. This engagement may be made by a point, edge, or outer surface contact of the angle portion 2i with the housing surface t, in similarity with the corresponding contacts made by the teeth of the ring S.

The spring ring like the spring ring has the general form of a frusturn of a come, ohci is inserted in the condenser housing with the tor down and the normal cone hase lacing outward.

This invention provides a simple and lucir pensive condenser housing and cover eomhlrlam tion, with the cover efficiently mechanically securecl and hermetically sealed ih the housing.

What is claimed is:

l.. In an electrolytic condenser assembly, a cylindrical plastic housing with che euri integrally forming chords or 'the closed and the other end open with an inner smooth surface having a straight longitudinal dimension extending inwardly t'o an annular shoulder; a cover disc of rigid insulating material with a disc of compressible material secured to its inner face, said cover disc being located in the open end of said housing in seating relation with said shoulder; and a spring-metal-coverretaining closed ring also in the open end of said housing, said closed ring having a plane annular surface in holding engagement with said cover,

and peripheral teeth angularly disposed with reing said shoulder and said outer member, and a peripherally toothed cover retaining ring also in said opening, said ring having a portion in holding relation with said cover and an angularly formed portion comprising said toothed periphery, in resilient out penetrating engagementwith the smooth walls of one of said surfaces in said housing, said electric terminal connection extending through the central portion of said ring, the outer pointed corners of each tooth engaging the inner smooth surface of said housing "with aA penetrating action, the outer surface of each Atooth between said corners beingv spacedfrom the inner surface of said housing.

'3. In an electrolytic condenser assembly, a cylindrical plastic housing with one end integrally closed and the other end open with an inner smooth surface having a straight longitudinal dimension extending inwardly to an annular shoulder, a cover disc of rigid insulating material. said cover disc being located in the open end of said housing in seating relation with said shoulder, and a spring-metal-cover-retaining closed ring also in the open end of said housing, said closed ring having a plane annular surface in holding engagement-with said cover, and peripheral teeth angularly disposed with respect ltosaid plane annular surface and in resilient but penetrating engagement with said inner surface-of said housing. v

GLENN W. CARPENTER.

REFERENCES -CTEiD The following references are of record in the le of this patent: A

UNITED STATES PATENTS Number Name Date 212,064 Spencer Feb. e, i879 780,732 Schmitt ----7 Jan. 2li,v 1905 '786,296 Keller Apr. d, 1905 929,974 McNu'tt Aug. 3, 1969 1,123,733 Grunwald l Jan. 5,1915 2,202,166 Peck May 23, 1940 '2,379,053 Weingart June 28. i945 

